delete AbstractSymbol

has not been used for a long time

src/main/java/de/tla2b/types/AbstractHasFollowers.java

@@ -45,8 +45,6 @@ public abstract class AbstractHasFollowers extends TLAType {
 				if (newType instanceof AbstractHasFollowers) {
 					((AbstractHasFollowers) newType).addFollower(follower);
 				}
-			} else if (follower instanceof AbstractSymbol) {
-				((AbstractSymbol) follower).setType(newType);
 			} else if (follower instanceof SetType) {
 				((SetType) follower).setSubType(newType);
 			} else if (follower instanceof TupleType) {

src/main/java/de/tla2b/types/AbstractSymbol.java

-package de.tla2b.types;
-
-public abstract class AbstractSymbol {
-
-	private TLAType type;
-
-	public AbstractSymbol(TLAType t) {
-		setType(t);
-	}
-
-	public TLAType getType() {
-		return type;
-	}
-
-	protected void setType(TLAType t) {
-		this.type = t;
-		if (type instanceof AbstractHasFollowers) {
-			AbstractHasFollowers p = (AbstractHasFollowers) t;
-			p.addFollower(this);
-		}
-	}
-}